Earlier this year, I started experiencing some hand and finger problems including pain and numbness. I was noticing it most near the end of a long day, and while using my mouse.
For a long time, I had been using (and loving) the Microsoft Wireless Optical Mouse 5000. I can't stand wired mice, and Optical is a must, so this mouse was a good fit for me. But, having 3 screens requires a lot of mouse movement, even with very high mouse speed.
When I mentioned my hand pain to Chris Spiess (coworker), he suggested switching to a trackball. He had hand problems many years ago, but they had subsided after switching to a trackball. I wasn't persuaded yet though. I had tried working at Chris's computer before, and I couldn't stand using the trackball. Using his computer made me feel like I was trying to draw a portrait with my left hand (I'm incredibly inept with my left hand). I didn't think I'd be able to adjust to the trackball.
About a week later though, Chris was out of the office for the day. I asked if I could borrow his trackball and try it at my station. What a difference! It turns out that my clumsiness with the trackball before was just because I was sitting at his desk, using his keyboard, from his chair. There were too many factors and overall, I was uncomfortable. At my workstation however, the trackball was very natural. I purchased one that very day; the same one he had--a Kensington Optical Expert Trackball Mouse 7.0 with scroll ring.
This device is awesome. The scroll ring is very, very nice. The programmable buttons are slick too. I have the upper-left button programmed as a double-click, which saves time and frustration many times. The click-lock is programmed as the combo of the bottom 2 buttons--and that's handy when moving windows. I love being able to just flick my fingers and move the cursor across 2 screens, even moving windows this way. I've gotten to be very precise with the trackball--more so than I could've ever gotten with a mouse. Best of all though: no hand or finger problems while computing anymore.
If you have a coworker that uses a trackball, see if you can borrow it at your station one day while he or she is out of the office. I've converted Jess Tedder by letting him borrow mine. He and I are both very happy we made the switch. And, thanks to Chris for the advice!